CN103819051B - A method for energy-saving treatment of liquor brewing wastewater - Google Patents

Abstract

The invention discloses an energy-saving processing method for wastewater generated during the liquor brewing process. The processing method comprises the following steps: (1) filtering the big floating dregs in liquor brewing wastewater with mechanical gratings; (2) then introducing the wastewater filtered by mechanical gratings into a comprehensive tank; (3) introducing the water discharged from the comprehensive tank into an anaerobic baffle-plate reactor; (4) introducing the water discharged from the anaerobic baffle-plate reactor into a medium precipitation tank; (5) introducing the water discharged from the medium precipitation tank into a composite vertical flow artificial wetland system, wherein in the artificial wetland system, pollutants such as organisms, SS, ammonia nitrogen, and the like in the wastewater are further degraded by the combined action of wetland substrate, microorganisms, and plants, and finally discharging the processed wastewater. The processing method can effectively remove the pollutants such as organisms, ammonia nitrogen, SS, and the like, in the liquor brewing wastewater on the basis of low equipment investment and operation management fee, moreover the water quality of the processed wastewater meets the I-grade discharge standard of the industry, and a novel method is provided for energy-saving treatment of liquor brewing wastewater.

Description

A method for energy-saving treatment of liquor brewing wastewater

technical field

The invention relates to a wastewater treatment method, in particular to an energy-saving treatment method for liquor brewing wastewater, and belongs to the technical field of food wastewater treatment.

Background technique

Liquor brewing wastewater mainly includes distillation bottom pot water, koji box cleaning water, printing koji wastewater, distiller's grain waste liquid, fermentation tank seepage water, grain soaking water, distillation cooling water, bottle washing water and equipment cleaning wastewater generated during the production process. . Wastewater generally does not contain heavy metals, has a high BOD/COD ratio and good biochemical properties, but the water quality and quantity fluctuate greatly in different periods. At the same time, the concentration of SS, COD _Cr and BOD ₅ in wastewater is relatively high and has a certain chroma. It is a typical high Concentrated organic wastewater, if discharged directly without treatment, will have a negative impact on the ecological environment.

At present, there are many treatment technologies for liquor brewing wastewater, such as chemical coagulation sedimentation method, micro-electrolysis method, concentrated combustion method, anaerobic biological treatment, aerobic biological treatment and anaerobic-aerobic combined process treatment method. In view of the high content of organic matter in this type of wastewater, biological methods are mainly used for treatment. Common main processes include contact oxidation, sequencing batch activated sludge (Sequencing Batch Reactor, SBR), cyclic activated sludge (Cyclic Activated Sludge System, CASS) and biological aerated filter (Biological Aerated Filter, BAF), etc. These processes have a common feature, which is the need for aeration equipment, and the price of the aeration fan is relatively high, and the power is relatively large, and its energy consumption accounts for a considerable part of the cost of wastewater treatment. At the same time, aeration equipment and pipelines need to be maintained frequently, otherwise the wastewater treatment effect may be affected due to insufficient aeration or uneven aeration. Therefore, it is of great practical significance to develop a liquor brewing wastewater treatment method with low construction, operation and maintenance costs and good treatment effect, both for the healthy development of liquor production enterprises and for the protection of the ecological environment. the

The Anaerobic Baffled Reactor (ABR) is a new type of high-efficiency anaerobic reactor developed by McCarty of Stanford University in the United States and his collaborators. Its structure can be regarded as a series of anaerobic reactors. Series operation of sludge bed reactors (Up-flow Anaerobic Sludge Bed, UASB). The ABR reactor is characterized by an acidification reaction chamber with independent compartments, which can separate the two steps of hydrogen production and methane production, thereby avoiding the inhibition caused by the excessive accumulation of propionic acid and butyric acid during the reaction process, and has a simple structure. , Generally, no filler, reflux and stirring equipment are required, the treatment effect is stable and reliable, and the construction and maintenance management costs are low.

Constructed wetland is a new ecological engineering technology for sewage treatment and resource utilization developed on the basis of the purification function of natural wetland. Good effect and other advantages. Its purification methods include filtration, adsorption, precipitation, ion exchange, plant absorption and microbial metabolism, etc. Through the synergistic effect of physics, chemistry and biology, it can effectively remove suspended solids, organic matter, nitrogen, phosphorus, heavy metals and pathogenic microorganisms in wastewater. Constructed wetlands can be divided into various types according to the flow state of wastewater in wetlands. Among them, the unique "downward-upward" water flow mode of composite vertical flow constructed wetlands effectively solves the "short circuit" phenomenon that is easy to occur in other types of wetlands. Composite water treatment structure with aerobic downstream pool and partially anaerobic upstream pool. At the same time, this technology can make full use of the comprehensive effects of substrates, plants and microorganisms, and has a significant removal efficiency for organic matter and suspended matter in wastewater.

Contents of the invention

The technical problem solved by the present invention is to provide a low-consumption and high-efficiency energy-saving treatment method for liquor brewing wastewater. According to the water quality characteristics and treatment process status of liquor brewing wastewater, a combined treatment process of "pre-acidification + ABR + composite vertical flow artificial wetland" is proposed After the liquor brewing wastewater is treated, the water quality can meet the requirements of the first-level discharge standard in the "Comprehensive Pollutant Discharge Standard" (GB 8978-1996), and the treatment cost is relatively low.

The technical solution of the present invention is: an energy-saving treatment method for liquor brewing wastewater, which is characterized in that it includes the following steps: (1) the liquor brewing wastewater is filtered through a mechanical grid to filter coarse floating objects in the water; (2) the wastewater is filtered through a mechanical grid Enter the comprehensive pool, which is composed of a sedimentation adjustment area and a pre-acidification area. The scum in the sedimentation adjustment area is scraped to the sand filter by a slag scraper. The sand filter is equipped with filter sand, and the filtrate filtered by the filter sand is used The mud pump is returned to the sedimentation adjustment area, and the settled sludge is pumped to the sludge thickening tank by the sludge pump. The total hydraulic retention time of the comprehensive pool is not less than 14 h, of which the hydraulic retention time of the sedimentation adjustment area is not less than 10 h, and the surface load is not greater than 0.8 m ³ /(m ² h), the effective sedimentation water depth is not less than 2 m, the volume of the sludge hopper is not less than 2 days of sludge volume, the single cell aspect ratio of the sedimentation adjustment area is not less than 4, and the aspect ratio is not less than 8. The wastewater enters the pre-acidification area after passing through the sedimentation adjustment area. The hydraulic retention time of the pre-acidification area is 3-5 h, where elastic packing is hung, and a submersible mixer is installed at the bottom, and the anaerobic microorganisms on the packing are used to pre-acidify the wastewater; ( 3) The effluent of the comprehensive pool enters the anaerobic baffle reactor, and the microbial flora decomposes and removes most of the organic pollutants in the wastewater under anaerobic conditions; (4) The effluent of the anaerobic baffle reactor enters the intermediate sedimentation tank , the intermediate sedimentation tank adopts the form of a vertical flow sedimentation tank, and the surface load is not more than 0.8 m ³ /(m ² h), further removes SS, prevents the blockage of the constructed wetland due to excessive SS, and the sludge returns to the anaerobic reflux Plate reactor; (5) The effluent from the intermediate sedimentation tank enters the composite vertical flow artificial wetland system, and under the joint action of the wetland matrix, microorganisms and plants, it further degrades and removes organic matter, SS and ammonia nitrogen pollutants in the wastewater before discharge.

In the method for energy-saving treatment of liquor brewing wastewater according to the present invention, in step (1), a water collection well is arranged behind the mechanical grid, and the effective volume of the water collection well (measured by the lowest design water level) is not less than the water output of the largest water pump in the well for 15 minutes, and the water pump The number of starts per hour is not more than 3, and the water pump adopts automatic liquid level control.

In the method for energy-saving treatment of liquor brewing wastewater according to the present invention, in step (3), the designed volume load of the anaerobic baffle reactor is not less than 3 kg COD/(m ³ ·d), and the pool body is divided into 4-6 grids, connected in series, The total hydraulic retention time is not less than 24 h, and the internal return flow is set, and the elastic packing is hung.

In the method for energy-saving treatment of liquor brewing wastewater according to the present invention, the wetland system in step (5) is composed of a downflow pool and an upflow pool connected in series, a partition wall is arranged between the two pools, and the bottom is connected, and the matrix in the downflow pool is gravel, from which It is divided into 3 layers from bottom to top, with particle sizes of 30-50 mm, 15-30 mm, and 5-15 mm; the bottom layer of the upstream flow pool is gravel with a particle size of 30-50 mm, and the middle layer is gravel with a particle size of 15-30 mm. Gravel, on which a geotextile filter layer is set, and the geotextile is filled with a mixed matrix of fine sand and blast furnace slag. The pool depths of the downflow pool and the upflow pool are 0.8-1.2 m, and the thickness of the matrix of the downflow pool is higher than that of the upflow pool. 10-30 cm, the slope of the bottom of the downflow pool and the upflow pool is 0.5%-1%, the hydraulic retention time of the downflow pool and the upflow pool is 12-24 h, the matrix of the downflow pool and the upflow pool Purification plants are planted on the upper side, water distribution pipes are laid on the surface of the downflow pool, collection pipes are arranged on the surface of the upflow pool, and emptying pipes are arranged on the substrate bottom of the downflow pool and the upflow pool. The sewage first flows downward through the water distribution pipe and passes through the downflow pool After the substrate layer at the bottom is collected, it passes through the partition wall and enters the upflow pool. In the upflow pool, the sewage is collected and discharged from the bottom to the top through the collection pipe.

Compared with the prior art, the present invention has the following advantages: (1) No aeration system is set in the wastewater treatment method of the present invention, which saves the investment and operation cost of aeration equipment; , SS concentration is high, and the water quality and quantity change greatly. The pre-acidification + ABR + composite vertical flow constructed wetland process is proposed to achieve the purpose of low-consumption and high-efficiency removal of pollutants in wastewater. After the liquor brewing wastewater is treated, the effluent can meet the requirements of the first-level discharge standard in the "Comprehensive Pollutant Discharge Standard" (GB 8978-1996).

Detailed ways

The above-mentioned content of the present invention will be further described in detail through the following examples, but it should not be understood that the scope of the above-mentioned subject of the present invention is limited to the following examples. All technologies realized based on the above content of the present invention belong to the scope of the present invention.

Example

In a liquor production enterprise, in addition to production wastewater, the wastewater produced also includes some domestic wastewater in the factory area. The wastewater volume is 350 m ³ /d. The raw water quality indicators are shown in Table 1.

Table 1 Waste water quality index (average value) of a liquor production enterprise

An energy-saving treatment method for liquor brewing wastewater, the specific steps are as follows:

(1) The waste water first flows through the mechanical grille, removes coarse particles and floating objects, and then flows into the sump, and then lifts it to the comprehensive pool by the first-stage lift pump;

(2) The waste water enters the comprehensive tank. In the sedimentation adjustment area, the scum in the water is scraped by the scraper to the sand filter tank. The sand filter tank is equipped with filter sand. After sand filtration, the filtrate is returned to the adjustment tank by a mud pump. The scum is regularly cleaned manually, and the suspended matter such as sediment is regularly pumped into the thickening tank with a mud pump. The wastewater enters the pre-acidification area after passing through the sedimentation adjustment area, where elastic fillers and submersible mixers are installed. Through pre-acidification, the difficult The biodegradable macromolecular substances are transformed into easily biodegradable small molecular substances to provide the biodegradability of wastewater to ensure the stable and efficient operation of subsequent treatment processes. The total hydraulic retention time of the comprehensive pool is not less than 14 h, and 15.6 h is selected in this experiment , the COD in the effluent is 2662 mg/L, the suspended solid concentration is 56 mg/L, the BOD ₅ is 1405 mg/L, and the ammonia nitrogen is 16.8 mg/L;

(3) The effluent from the comprehensive pool flows into the ABR reactor. In order to make the influent water evenly distributed, the influent water adopts a water distribution system. The reactor is equipped with elastic fillers. Microorganisms degrade most of the organic matter in the wastewater under anaerobic conditions. ABR The depth of the reactor is 6m, and 4-6 grids are connected in series. In this experiment, 4 grids are selected in series. The container load is not less than 3 kg/(m ³ ·d). In this experiment, the design volume load is 3.2 kg/(m ³ ·d). The time is not less than 24 h, and 34 h is selected in this experiment, and the effluent part is refluxed;

(4) The effluent from the ABR reactor flows into the vertical flow intermediate sedimentation tank, and the surface load is not greater than 0.8 m ³ /(m ² h). This experiment selects 0.8 m ³ /(m ² h), and the sludge returns to the ABR In the reactor, the COD in the effluent of the intermediate sedimentation tank is 346 mg/L, the concentration of suspended solids is 27 mg/L, the BOD ₅ is 154 mg/L, and the ammonia nitrogen is 14.4 mg/L;

(5) The effluent from the intermediate sedimentation tank is collected by the overflow weir and then flows into the composite vertical flow artificial wetland to further remove organic matter, ammonia nitrogen and suspended solids. The total area of the wetland is 450 m ² . 15 m), which are called the downflow pool and the upflow pool respectively. There is a partition wall in the middle of the two pools, and the bottom is connected. The slope of the bottom of the pool is 0.5%-1%. The time is 12-24 h. In this experiment, the hydraulic retention time is selected as 20 h. The depth of the downflow pool is 110 cm. The bottom layer is paved with gravel with a particle size of 30-50 mm and a thickness of 20 cm. The middle layer is gravel with a particle size of 15-30 mm and a thickness of 50 cm. cm, the upper layer is gravel with a particle size of 5-15 mm, and the thickness is 40 cm. The depth of the upflow pool is 90 cm. 40 cm, a geotextile filter layer is set on it, and the geotextile is filled with a mixed matrix of fine sand and blast furnace slag with a small particle size and a certain proportion, with a thickness of 30 cm. Canna genaralis is planted on the surface of the wetland, and finally the water is discharged The COD is 57 mg/L, the suspended solid concentration is 11 mg/L, the BOD ₅ is 21 mg/L, and the ammonia nitrogen is 11.5 mg/L. All water quality indicators of the effluent are better than the "Comprehensive Pollutant Discharge Standard" (GB 8978- 1996) Tier 1 emission standard.

The above embodiments describe the basic principles, main features and advantages of the present invention. Those skilled in the industry should understand that the present invention is not limited by the above-mentioned embodiments, and that described in the above-mentioned embodiments and the specification only illustrates the principle of the present invention, and the present invention also has various aspects without departing from the scope of the principle of the present invention. Changes and improvements, these changes and improvements all fall within the protection scope of the present invention.

Claims (4)

1. An energy-saving treatment method for liquor brewing wastewater, which is characterized in that it comprises the following steps: (1) the liquor brewing wastewater is filtered through a mechanical grid to filter coarse floating objects in the water; (2) the wastewater filtered through the mechanical grill enters a comprehensive pool, and the integrated The tank is composed of a sedimentation adjustment area and a pre-acidification area. The scum in the water in the sedimentation adjustment area is scraped by the scraper to the sand filter tank. The sand filter tank is equipped with filter sand, and the filtrate filtered by the filter sand is pumped back to the sediment by a mud pump. In the conditioning area, the settled sludge is pumped to the sludge thickening tank by the sludge pump. The total hydraulic retention time of the comprehensive pool is not less than 14 h, of which the hydraulic retention time of the sedimentation conditioning area is not less than 10 h, and the surface load is not greater than 0.8 m ³ /( m ² h), the effective water depth for sedimentation is not less than 2 m, the volume of the sludge hopper is not less than 2 days of sludge volume, the aspect ratio of a single cell in the sedimentation adjustment area is not less than 4, and the aspect ratio is not less than 8. After the adjustment area, it enters the pre-acidification area. The hydraulic retention time of the pre-acidification area is 3-5 hours, in which elastic packing is hung, and a submersible mixer is installed at the bottom, and the anaerobic microorganisms on the packing are used to pre-acidify the wastewater; (3) The effluent of the comprehensive pool Entering the anaerobic baffle reactor, the microbial flora decomposes and removes most of the organic pollutants in the wastewater under anaerobic conditions; (4) The effluent from the anaerobic baffle reactor enters the intermediate sedimentation tank, and the intermediate sedimentation tank adopts In the form of a vertical flow sedimentation tank, the surface load is not more than 0.8 m ³ /(m ² h), further removes SS, prevents the clogging of the constructed wetland due to excessive SS, and the sludge returns to the anaerobic baffle reactor; ( 5) The effluent from the intermediate sedimentation tank enters the composite vertical flow artificial wetland system, and under the joint action of the wetland matrix, microorganisms and plants, it further degrades and removes organic matter, SS and ammonia nitrogen pollutants in the wastewater before being discharged. 2. The method for energy-saving treatment of liquor brewing wastewater according to claim 1, characterized in that: in the step (1), a water collection well is set behind the mechanical grille, and the effective volume of the water collection well is not less than the maximum one in the well in terms of the lowest design water level. The water output of one water pump in 15 minutes, and the number of starts of the water pump per hour is not more than 3, and the water pump adopts automatic liquid level control. 3. The method for energy-saving treatment of liquor brewing wastewater according to claim 1, characterized in that: in the step (3), the designed volume load of the anaerobic baffle reactor is not less than 3 kg COD/(m ³ ·d) , The pool body is divided into 4-6 grids, connected in series, the total hydraulic retention time is not less than 24 h, internal reflux is set, and elastic fillers are hung. 4. The method for energy-saving treatment of liquor brewing wastewater according to claim 1, characterized in that: in the step (5), the wetland system is composed of a downflow pool and an upflow pool connected in series, and a partition wall is arranged between the two pools, and the bottom Connected, the substrate in the downstream flow pool is gravel, which is divided into 3 layers from bottom to top, with particle sizes of 30-50 mm, 15-30 mm, and 5-15 mm; the bottom layer of the upstream flow pool is 30-50 mm in particle size Gravel, the middle layer is gravel with a particle size of 15-30 mm, and a geotextile filter layer is set on it, and the geotextile is filled with a mixed matrix of fine sand and blast furnace slag, and the pool depths of the downflow pool and the upflow pool are 0.8-1.2 m respectively , the substrate thickness of the downflow pool is 10-30 cm higher than that of the upflow pool, the slope of the bottom of the downflow pool and the upflow pool is 0.5%-1%, and the hydraulic retention time of the downflow pool and the upflow pool is 12-24 h, purification plants are planted on the substrate of the downflow pool and the upflow pool, water distribution pipes are laid on the surface of the downflow pool, collection pipes are arranged on the surface of the upflow pool, and emptying pipes are arranged on the substrate bottom of the downflow pool and the upflow pool, and the sewage first It flows downward through the water distribution pipe, passes through the matrix layer of the downflow pool, collects in the connected layer at the bottom, passes through the partition wall and enters the upflow pool. In the upflow pool, the sewage is collected and discharged from the bottom to the top through the collection pipe.